Miscibility Evaluation of LDPE/EVA Blends Filled with Lignin by Rheological Properties and FT-IR

Abstract

Lignin, one kind of byproduct of pulp-making industry, is used for the preparation of blends with LDPE/EVA by torque rheometer through the measuring maximal torque, balanced torque and plasticized time to confirm the optimum processing conditions. The miscibility, which is mainly dependent on the occurrence of lignin-polymer interactions of hydrogen bond, is characterized by Fourier infrared spectroscopic analysis (FT-IR). The results indicate that the rheological properties of lignin filled blends with 50~55N•maximal torque, 11~12N•m balanceable torque and 60~70s plasticized time are obtained under the conditions of 20 parts lignin blending with the LDPE and EVA proportion of 55/45 with 10 parts compatibilizer at 150°C. The FT-IR figures show that the hydrogen bond between compatibilizer and lignin or polymer is formed resulting from that the characteristic absorption peak of carbonyl at 1725~1800cm-1 disappears and hydroxide at 3438~3440cm-1 increases.